1. Field of the Invention
This invention relates to a time series signal multichannel frequency analyzer using a liquid crystal panel.
2. Prior Art Statement
In the laser-Doppler velocity measurement method (LDV), the velocity of a moving body is determined from the change occurring in the frequency of a laser beam reflected off the body owing to the Doppler effect. LDV thus requires analysis of the frequency distribution of the reflected laser beam. LDV is also used for determining the center of rotation of rotating bodies. In this case, to determine the center with high-precision, it is necessary to measure the velocity of a number of points on the rotating body simultaneously and then to analyze the frequencies of the velocity signals obtained. The conventional method of conducting this analysis by computation using electric circuitry requires much time for the computations, so that it is impossible to achieve high-speed analysis.
One way of speeding up the frequency analysis is to subject the time series signals obtained by LDV to optical Fourier-transformation after writing them directly to an optical element. An optical time series signal Fourier transformation method using an acoustooptical device has been devised for this.
Since multichannel frequency analysis is difficult to achieve by this optical Fourier transformation method, however, the method cannot be practically applied in cases where there are a large number of signal sources, for example, where several tens of channel signals have to be simultaneously processed,